In general, an Edge extension cannot prevent the user from uninstalling it, so LeechBlock cannot offer this as an option within the extension itself.

However, it is possible to “force install” an extension by setting a Microsoft Edge policy so that the extension cannot be removed or disabled. (You should create a backup of your LeechBlock settings before you attempt this solution: Options > General > Export.)

On Windows, the policy can be set via the Registry Editor:

• Navigate to the following registry key (or create it if it doesn’t exist):
  • HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Edge
• Add a new key under the Edge key (if it doesn’t already exist):
  • ExtensionInstallForcelist
• Add a new value to that key:
  • Name: 1 (or some higher number if 1 is already used)
  • Type: String (REG_SZ)
  • Data: hnncfhodpmpjchmmcnimoimkcojdmfhl

Warning: Do not attempt to edit the registry unless you really know what you’re doing! You should back up your registry before making any changes. The developer of LeechBlock will not be held responsible for any damage you do to your system by editing the registry.